One problem associated with one commonly used brake system for e.g. heavier vehicles is that the actuating means, which alter the brake pad units between braking and released positions, have end sections which, during certain conditions e.g. during adjustment for the gradual wear of the brake pad units, are affected by torsional forces, which can result in damage to e.g. covering boots and the like with the accompanying deterioration of their function as dirt protection sealing means.